Electromagnetic radiation mitigation in coatings with spherical particles

ABSTRACT

Coating compositions comprising a polymer binder and a sphere selected from porous metal oxide spheres formed from metal oxide particles and having, e.g., an average porosity of from 0.10 to 0.90; polymer spheres formed from a multimodal distribution of polymer particles; or mixtures thereof, are described herein. The sphere enhances the reflective characteristics of the coating compositions with respect to electromagnetic radiation. In particular, the coating compositions when dried, can exhibit UV reflectance, visible light reflectance, IR reflectance, or a combination thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/817,259, entitled “Electromagnetic Radiation Mitigation inCoatings with Spherical Particles,” filed Mar. 12, 2019, the content ofwhich is herein incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to coating compositions, particularly tocoating compositions comprising reflective spheres.

BACKGROUND

One important requirement for conservation of coatings is theirprotection from damage caused by environmental conditions. A primaryenvironmental concern is radiation including ultraviolet (UV), visible,and infrared (IR) radiation. Molecules of all types are excited by andselectively absorb energy from radiation at specific wavelengths acrossthe electromagnetic spectrum. For example, most organic polymers used incoatings are excited by and absorb radiation at a variety of specificwavelengths in the IR and UV regions of the electromagnetic spectrum.While the exact nature of the changes will depend upon the organicpolymer structure, the net effect of radiation is a marked change(deterioration) in physical, chemical, and performance properties of thecoatings. Heat is also a direct consequence of either visible orinfrared radiation incident on coatings.

Coatings having various functionalities, specifically how they interactwith natural electromagnetic radiation, is commonly adopted in thecoating industry. Coatings are designed to reflect or absorb certainwavelengths of incident radiation, depending upon the application.Currently, a wide range of technologies exists to help mitigate thesevarious incident wavelengths of radiation. However, there is still aneed for coatings with improved electromagnetic radiation mitigationeffects. The compositions and methods described herein address these andother needs.

SUMMARY OF THE DISCLOSURE

Coating compositions comprising a polymer binder and a sphere (e.g.,microsphere) selected from porous metal oxide spheres (e.g.,microspheres) formed from metal oxide particles (e.g., nanoparticles)and having an average porosity of from 0.10 or 0.30 to 0.80 or 0.90;polymer spheres (e.g., microspheres) formed from a multimodaldistribution of polymer particles (e.g., nanoparticles); or mixturesthereof, are described herein. The sphere can have an average particlesize diameter of 100 microns or less, or from 1 micron to 100 microns.The problem solved with the use of the sphere includes enhancement ofthe reflective characteristics of the coating compositions with respectto electromagnetic radiation. In particular, the coating compositionswhen dried, can exhibit UV reflectance within a wavelength from 100 nmto 400 nm, visible light reflectance within a wavelength of from 400 to700 nm, IR reflectance within a wavelength from 800 nm to 10 μm, or acombination thereof. The compositions may also exhibit improved opacitywithin a wavelength from 100 nm to 800 nm. In some instances, thecoating compositions can be an aqueous composition.

The polymer binder present in the coating compositions can comprise apolymer selected from acrylic homopolymers, styrene-acrylic-basedcopolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene block copolymers, vinyl acrylic-basedcopolymers, ethylene vinyl acetate-based copolymers, polychloroprene,alkyd resin, polyester resins, polyurethane resins, silicone resins,petroleum resins, epoxy resins, or blends thereof. The polymer bindercan be present in an amount of from greater than 0% to 99.9% by weight,or from 5% to 99.9% by weight, or from 10% to 95% by weight, based on adry weight of the coating composition.

As described herein, the sphere in the coating compositions can beselected from porous metal oxide spheres, polymer spheres, or mixturesthereof. In some examples, the coating compositions comprise the porousmetal oxide spheres. The porous metal oxide spheres can have an averageporosity from 0.10 to 0.80 or 0.90, from 0.20 to 0.70, from 0.40 toabout 0.65, or from 0.45 to about 0.55. The porous metal oxide spherescan have a multimodal distribution of pore sizes, such as a bimodaldistribution of pore sizes. The average pore diameter of the porousmetal oxide spheres can be from 50 nm to 10 μm, from 50 nm to 5 μm, from50 nm to 2.5 μm, or from 50 nm to 1 μm. The porous metal oxide spherescomprise from 60% to 99.9% by weight metal oxide, based on a totalweight of the porous metal oxide spheres. The metal oxide can beselected from the group consisting of silica, titania, alumina,zirconia, ceria, iron oxides, zinc oxide, chromium oxide andcombinations thereof, such as titania or silica.

In other examples, the coating compositions comprise the polymerspheres. The polymer spheres are formed from a polymodal, such as abimodal distribution of polymer particles. The polymer spheres cancomprise a polymer selected from the group consisting ofpoly(meth)acrylic acid, poly(meth)acrylates, polystyrenes,polyacrylamides, polyethylene, polypropylene, polylactic acid,polyacrylonitrile, blends thereof, salts thereof, and copolymersthereof.

The coating compositions can further comprise one or more pigments orfillers, for example, pigments or fillers selected from clay, kaolin,mica, titanium dioxide, talc, natural silica, synthetic silica, naturalsilicates, synthetic silicates, feldspars, nepheline syenite,wollastonite, diatomite, barite, glass, and calcium carbonate,bentonite, attapulgite, zeolite, or mixtures thereof. The one or morepigments or fillers can be present in an amount such that the sphere andone or more pigments or fillers make up from greater than 0% to 90% byweight, or from 0.1% to 60% by weight, based on a total weight of thecoating composition.

The coating compositions can further include a pigment dispersant, aninorganic or organic filler, a pigment extender, an adhesion enhancer, afilm forming aid, a defoamer, a thickener, a light stabilizer, a wettingagent, a biocide, a tackifier, or a combination thereof.

In specific examples, the coating compositions can be UV reflectivecomposition, such as clear coating compositions. Clear coatingcompositions comprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, blends thereof, or copolymersthereof; and a sphere comprising porous metal oxide spheres formed frommetal oxide particles, wherein the sphere has an average particle sizediameter of from 1 micron to 10 microns, from 1 micron to 5 microns, orfrom 1 micron to 3 microns, and wherein the clear coating compositionwhen dried exhibits a UV reflectance at a wavelength range from 100 nmto 400 nm, are disclosed herein. In certain embodiments, the UVreflective compositions comprise porous metal oxide spheres having anaverage diameter of from 1 micron to 10 microns, from 1 micron to 5microns, or from 1 micron to 3 microns; an average porosity of from 0.20to 0.70 or from 0.45 to 0.55; and an average pore diameter of from 50 nmto 400 nm or from 50 nm to 200 nm. The UV reflective compositions canfurther comprise one or more UV absorbers, such as those selected from ahydroxy-phenyl-benzotriaziole, a hydroxy-phenyl-triazine, ahydroxyl-benzophenone, an oxanilide, a cyanoacrylate, a malonate, and amixture thereof.

In other specific examples, the coating compositions exhibits improvedopacity, such as when incorporated in paints. Paint compositionscomprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, blends thereof, or copolymersthereof; and a sphere selected from porous metal oxide spheres formedfrom metal oxide particles, polymer spheres formed from a multimodaldistribution of polymer particles, or a mixture thereof, wherein thesphere has an average particle size diameter of, e.g., 100 microns orless, from 1 micron to 100 microns, or from 1 micron to 10 microns, andan average porosity of from 0.40 to 0.65 or from 0.45 to 0.55, aredisclosed herein. In certain embodiments, the coating compositionsexhibiting improved opacity comprise porous metal oxide spheres havingan average diameter of from 1 micron to 100 microns or from 1 micron to10 microns; an average porosity of from 0.20 to 0.70, or from 0.45 to0.55; and an average pore diameter of from 50 nm to 800 nm, from 50 nmto 400 nm, or from 100 nm to 200 nm. A wet film having a thickness of 75μm and formed from the coating compositions exhibiting improved opacitysuch as paint compositions can exhibit a light scattering coefficient ofgreater than 1 S/mil, or greater than 3 S/mil, and an absorptioncoefficient of less than 0.02 K, as determined according to BS EN ISO6504-1. The film can exhibit a contrast ratio of at least 90% or greaterthan 96%. Compositions having improved opacity can be selected from anaqueous based paint or an oil based paint or selected from an industrialpaint or an architectural paint for interior and exterior applications.

In further specific examples, the coating compositions can be IRreflective coating composition. IR reflective coating compositioncomprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, alkyd resin, polyesterresins, polyurethane resins, silicone resins, petroleum resins, epoxyresins, blends thereof, or copolymers thereof; and a sphere selectedfrom porous metal oxide spheres formed from metal oxide particles,polymer spheres formed from a multimodal distribution of polymerparticles, or a mixture thereof, wherein the sphere has, e.g., anaverage particle size diameter of 5 microns or greater or from 5 micronsto 100 microns and an average porosity of from 0.40 to 0.65 or from 0.45to 0.55, and wherein the coating composition when dried exhibits an IRreflectance at a wavelength range from, e.g., 800 nm to 10 microns, from800 nm to 2.5 microns, or from 800 nm to 1 micron, are disclosed herein.In certain embodiments, the IR reflective coating compositions compriseporous metal oxide spheres having an average diameter of from greaterthan 5 microns to 100 microns; an average porosity of from 0.20 to 0.70or from 0.45 to 0.55; and an average pore diameter of from 400 nm to 5microns, from 400 nm to 2.5 microns, or from 400 nm to 1 micron.

Coatings and films formed from the coating compositions are alsodisclosed. The coating compositions can be in the form of an ink or anarchitectural coating, such as a paint. The films can have a thicknessof from 0.5 to 500 microns, or a thickness of from 5 to 75 microns, orfrom 0.5 to 30 microns, after drying. In certain embodiments, the filmscan exhibit a UV reflectance at a wavelength from 100 nm to 400 nm of atleast 10%, at least 20%, at least 40%, or at least 50%. In otherembodiments, the films can exhibit an IR reflectance at a wavelengthfrom 800 nm to 10 μm, from 800 nm to 5 μm, from 800 nm to 2.5 μm, orfrom 800 nm to 1 μm, of at least 10%, at least 20%, at least 40%, or atleast 50%. In further embodiments, the films having a thickness of 75microns, exhibit a contrast ratio of at least 90% or at least 96%.

Methods of protecting a substrate against UV-radiation or IR-radiationcomprising applying a coating composition disclosed herein are alsoprovided. The substrate can be an architectural structure, glass, metal,wood, plastic, concrete, vinyl, ceramic material or another coatinglayer applied on such a substrate.

The details of one or more embodiments are set forth in the descriptionbelow. Other features, objects, and advantages will be apparent from thedescription and from the claims.

DETAILED DESCRIPTION

This disclosure is based on the discovery that the physicalcharacteristics of spheres (e.g., microspheres) selected from porousspheres (also referred to herein as porous metal oxide spheres) formedfrom metal oxide particles (e.g., nanoparticles), polymer spheres (e.g.,microspheres) formed from a multimodal distribution of polymer particles(e.g., nanoparticles), or mixtures thereof can be tuned to enhanceperformance properties of coating compositions. The terms “tuned,”“adjusted,” and “configured” can be used interchangeably and refer to anadjustment to a physical and/or chemical characteristic of the spheresto change the reflectance properties of the spheres. By way of example,and not to be considered limiting, such physical characteristics thatcan be adjusted include the spheres' particle size diameter, particlesize distribution, particle shape, the void (pore) diameter within thespheres, porosity, packing density, surface texture, and the degree oforder with regards to the spatial arrangement of the voids (pores) inthe spheres. Chemical characteristics that can be adjusted include thechemical make-up of the spheres. When used in coating compositions, thespheres can be added in a sufficient amount to enhance reflectiveproperties and optionally replace existing components such as pigmentsand/or fillers in the coating compositions.

“Coating compositions” as used herein is a generic term for surfacecoatings and refers to compositions that include a vehicle containing apolymer binder component and a pigment or filler dispersed into thevehicle. The coating compositions described herein can include anaqueous or non-aqueous vehicle; a polymer binder; a sphere selected fromporous metal oxide spheres, polymer spheres, or combinations thereof;and optionally one or more pigments or fillers. The coating compositionswhen dried, exhibit UV reflectance, visible light reflectance, IRreflectance, or a combination thereof. Preferably, the dried coatingcompositions exhibit a UV, visible, or IR reflectance of at least 10%,20% or greater, 30% or greater, 40% or greater, or 50% or greater.Reflectance or reflectivity is expressed in terms of percentage ofincident light that is scattered or reflected away from a surface.

In certain embodiments, the coating compositions comprising the spheresdisclosed herein provide UV absorption functionality. The coatingcompositions can be coated on or incorporated into a substrate. Thesubstrate can include, e.g., plastics, wood, fibers or fabrics,ceramics, glass, metals, and composite products thereof.

Polymer Binder

As described herein, the coating compositions include a polymer binderand sphere. The term “binder” (which also may be referred tointerchangeably as “resin”) refers to polymers that are included in thecoating composition and that augment or participate in film formationand in the composition of the resultant film.

The specific polymer in the polymer binder can depend on the applicationof the coating compositions as well as other components of the coatingcompositions, such as an aqueous or non-aqueous vehicle. In someembodiments, the polymer binder can include a polymer selected fromacrylic homopolymers (i.e., a polymer derived from one or more acrylicmonomers), styrene-acrylic-based copolymers (i.e., a polymer derivedfrom styrene and one or more (meth)acrylic monomers),styrene-butadiene-based copolymers (i.e., a polymer derived from styreneand one or more diene monomers such as 1,2-butadiene, 1,3-butadiene,2-methyl-1,3-butadiene, or 2-chloro-1,3-butadiene),styrene-butadiene-styrene block copolymers, vinyl acrylic-basedcopolymers (i.e., a polymer derived from one or more vinyl estermonomers and one or more (meth)acrylic monomers), ethylene vinylacetate-based copolymers (i.e., a polymer derived from ethylene andvinyl acetate), a vinyl chloride-based polymer (i.e., a polymer derivedfrom one or more vinyl chloride monomers such as polyvinyl chloride),polychloroprene (i.e., a polymer derived from chlorinated dienemonomers), a vinyl alkanoate-based polymer (i.e., a polymer derived fromone or more vinyl alkanoate monomers, such as polyvinyl acetate or acopolymer derived from ethylene and vinyl acetate monomers), alkydresin, polyester resin, polyurethane resin, an acrylic-polyurethanehybrid polymer, silicone resin, petroleum resin, epoxy resin, or blendsthereof.

In certain embodiments, the polymer (e.g., an acrylic homopolymer or astyrene-acrylic based copolymer) in the polymer is derived from one ormore (meth)acrylate and/or (meth)acrylic acid monomers. The term“(meth)acryl . . . ,” as used herein, includes acryl . . . , methacryl .. . , and also includes diacryl . . . , dimethacryl . . . polyacryl . .. and polymethacryl . . . or mixtures thereof. For example, the term“(meth)acrylate monomer” includes acrylate and methacrylate monomers,diacrylate and dimethacrylate monomers, and other polyacrylate andpolymethacrylate monomers. Suitable (meth)acrylate monomers includeesters of α,β-monoethylenically unsaturated mono- and dicarboxylic acidshaving 3 to 6 carbon atoms with alkanols having 1 to 12 carbon atoms(e.g. esters of acrylic acid, methacrylic acid, maleic acid, fumaricacid, or itaconic acid, with C₁-C₁₂, C₁-C₈, or C₁-C₄ alkanols such asethyl, n-butyl, isobutyl and 2-ethylhexyl acrylates and methacrylates,dimethyl maleate and n-butyl maleate). Specific examples of suitable(meth)acrylate monomers for use in the polymer binder include methyl(meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl(meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate,n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-heptyl(meth)acrylate, 2-methylheptyl (meth)acrylate, octyl (meth)acrylate,isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl(meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl(meth)acrylate, heptadecyl (meth)acrylate, lauryl (meth)acrylate,tridecyl (meth)acrylate, stearyl (meth)acrylate, glycidyl(meth)acrylate, allyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate,cyclohexyl (meth)acrylate, 2-propylheptyl (meth)acrylate, behenyl(meth)acrylate, or combinations thereof. Other suitable (meth)acrylatemonomers include alkyl crotonates, acetoacetoxyethyl (meth)acrylate,acetoacetoxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate,2-ethoxyethyl (meth)acrylate, 2-methoxy (meth)acrylate,2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate,caprolactone (meth)acrylate, polypropyleneglycol mono(meth)acrylate,polyethyleneglycol (meth)acrylate, benzyl (meth)acrylate,2,3-di(acetoacetoxy)propyl (meth)acrylate, hydroxypropyl (meth)acrylate,methylpolyglycol (meth)acrylate, 3,4-epoxycyclohexylmethyl(meth)acrylate, 1,6 hexanediol di(meth)acrylate, 1,4 butanedioldi(meth)acrylate, or combinations thereof.

The polymer in the polymer binder can include a (meth)acrylate monomerin an amount of 5% or greater by weight, based on the weight of thepolymer. For example, the (meth)acrylate monomer can be in an amount of7% or greater, 10% or greater, 20% or greater, 30% or greater, 40% orgreater, 50% or greater, 60% or greater, 65% or greater, 70% or greater,75% or greater, 80% or greater, 85% or greater, 90% or greater, 95% orgreater, or up to 100% by weight, based on the weight of the polymer. Insome embodiments, the (meth)acrylate monomer can be in an amount of 100%or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% orless, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less,45% or less, 40% or less, 35% or less, 30% or less, or 25% or less, byweight, based on the weight of the polymer. The polymer can be derivedfrom any of the minimum values to any of the maximum values by weightdescribed above of the (meth)acrylate monomers. For example, the(meth)acrylate monomer can be in an amount of from greater than 0% to100%, 20% to 100%, 40% to 95%, 50% to 95%, 65% to 95%, or 65% to 85% byweight, based on the weight of the polymer.

In certain embodiments, the polymer in the polymer binder can be derivedfrom (meth)acrylic acid monomers. Examples of suitable (meth)acrylicacid monomers include α,β-monoethylenically unsaturated mono- anddicarboxylic acids having 3 to 6 carbon atoms. Specific examples ofsuitable (meth)acrylic acid monomers include acrylic acid, methacrylicacid, maleic acid, fumaric acid, or itaconic acid, crotonic acid,dimethacrylic acid, ethylacrylic acid, allylacetic acid, vinylaceticacid, mesaconic acid, methylenemalonic acid, citraconic acid, ormixtures thereof. The polymer can be derived from 0%, 0.5% or greater,1.0% or greater, 1.5% or greater, 2.5% or greater, 3.0% or greater, 3.5%or greater, 4.0% or greater, or 5.0% or greater, by weight of a(meth)acrylic acid monomer. In some embodiments, the polymer can bederived 25% or less, 20% or less, 15% or less, or 10% or less, by weightof a (meth)acrylic acid monomer. In some embodiments, the polymer can bederived from 0.5%-25%, from 0.5%-10%, from 1.0%-9%, from 2.0%-8% or from0.5%-5%, by weight of a monomer.

In certain embodiments, the polymer in the polymer binder includes vinylaromatic monomers (e.g., styrene). For example, the polymer binder caninclude a styrene-acrylic-based copolymer, a styrene-butadiene-basedcopolymer, a styrene-butadiene-styrene block copolymer, or a mixturethereof. Suitable vinyl aromatic monomers for use in the copolymers caninclude styrene or an alkyl styrene such as α- and p-methylstyrene,α-butylstyrene, p-n-butylstyrene, p-n-decylstyrene, vinyltoluene, andcombinations thereof. The vinyl aromatic monomer can be present in anamount of 0% by weight or greater (e.g., 1% or greater, 2% or greater,5% or greater, 10% or greater, 15% or greater, 20% or greater, 25% orgreater, 30% or greater, 40% or greater, 50% or greater, 60% or greater,65% or greater, 70% or greater, 75% or greater, 80% or greater, or 85%or greater by weight), based on the total weight of monomers from whichthe polymer is derived. In some embodiments, the vinyl aromatic monomercan be present in the polymer in an amount of 90% by weight or less(e.g., 85% or less, 80% or less, 75% or less, 70% or less, 65% or less,60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% orless, 30% or less, 25% or less, 15% or less, or 10% or less by weight),based on the total weight of monomers from which the polymer is derived.The polymer can be derived from any of the minimum values to any of themaximum values by weight described above of the vinyl aromatic monomer.For example, the polymer can be derived from 0% to 90% by weight (e.g.,from 0% to 60%, from 0% to 45%, from 2% to 85%, from 2% to 60%, from 2%to 40%, from 5% to 85%, from 5% to 75%, from 5% to 60%, from 5% to 50%,from 5% to 35%, from 0% to 15%, from 0% to 10%, from 2% to 10%, or from0% to 5% by weight of vinyl aromatic monomer), based on the total weightof monomers from which the polymer is derived.

When used, the styrene-acrylic-based copolymer can include styrene, a(meth)acrylate monomer, and optionally, one or more additional monomers.In some embodiments, the weight ratio of styrene to the (meth)acrylatemonomer in the polymer can be from 1:99 to 99:1, from 10:99 to 99:10,from 5:95 to 95:5, from 5:95 to 80:20, from 20:80 to 80:20, from 5:95 to70:30, from 30:70 to 70:30, or from 40:60 to 60:40. For example, theweight ratio of styrene to the (meth)acrylate monomer can be 25:75 orgreater, 30:70 or greater, 35:65 or greater, or 40:60 or greater. Insome examples, the polymer can be a random copolymer, such as a randomstyrene-(meth)acrylate copolymer.

In certain embodiments, the polymer in the polymer binder can be derivedfrom one or more ethylenically-unsaturated monomers selected fromanhydrides of α,β-monoethylenically unsaturated mono- and dicarboxylicacids (e.g. maleic anhydride, itaconic anhydride, and methylmalonicanhydride); acrylamides and alkyl-substituted acrylamides (e.g.(meth)acrylamide, N-tert-butylacrylamide, and N-methyl(meth)acrylamide);(meth)acrylonitrile; 1,2-butadiene (i.e. butadiene); vinyl andvinylidene halides (e.g. vinyl chloride and vinylidene chloride); vinylesters of C₁-C₁₈ mono- or dicarboxylic acids (e.g. vinyl acetate, vinylpropionate, vinyl n-butyrate, vinyl laurate and vinyl stearate); C₁-C₄hydroxyalkyl esters of C₃-C₆ mono- or dicarboxylic acids, especially ofacrylic acid, methacrylic acid or maleic acid, or their derivativesalkoxylated with from 2 to 50 moles of ethylene oxide, propylene oxide,butylene oxide or mixtures thereof, or esters of these acids with C₁-C₁₈alcohols alkoxylated with from 2 to 50 mole of ethylene oxide, propyleneoxide, butylene oxide or mixtures thereof (e.g. hydroxyethyl(meth)acrylate, hydroxypropyl (meth)acrylate, and methylpolyglycolacrylate); monomers containing glycidyl groups (e.g. glycidylmethacrylate); linear 1-olefins, branched-chain 1-olefins or cyclicolefins (e.g., ethene, propene, butene, isobutene, pentene,cyclopentene, hexene, and cyclohexene); vinyl and allyl alkyl ethershaving 1 to 40 carbon atoms in the alkyl radical, wherein the alkylradical can possibly carry further substituents such as a hydroxylgroup, an amino or dialkylamino group, or one or more alkoxylated groups(e.g., methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether,isobutyl vinyl ether, 2-ethylhexyl vinyl ether, vinyl cyclohexyl ether,vinyl 4-hydroxybutyl ether, decyl vinyl ether, dodecyl vinyl ether,octadecyl vinyl ether, 2-(diethylamino)ethyl vinyl ether,2-(di-N-butylamino)ethyl vinyl ether, methyldiglycol vinyl ether, andthe corresponding allyl ethers); sulfo-functional monomers (e.g.,allylsulfonic acid, methallylsulfonic acid, styrenesulfonate,vinylsulfonic acid, allyloxybenzenesulfonic acid,2-acrylamido-2-methylpropanesulfonic acid, and their correspondingalkali metal or ammonium salts, sulfopropyl acrylate, and sulfopropylmethacrylate); vinylphosphonic acid, dimethyl vinylphosphonate, andother phosphorus monomers (e.g., phosphoethyl (meth)acrylate);alkylaminoalkyl (meth)acrylates or alkylaminoalkyl(meth)acrylamides orquaternization products thereof (e.g., 2-(N,N-dimethylamino)ethyl(meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate,2-(N,N,N-trimethylammonium)ethyl (meth)acrylate chloride,2-dimethylaminoethyl(meth)acrylamide,3-dimethylaminopropyl(meth)acrylamide, and3-trimethylammoniumpropyl(meth)acrylamide chloride); allyl esters ofC₁-C₃₀ monocarboxylic acids; N-vinyl compounds (e.g., N-vinylformamide,N-vinyl-N-methylformamide, N-vinylpyrrolidone, N-vinylimidazole,1-vinyl-2-methylimidazole, 1-vinyl-2-methylimidazoline,N-vinylcaprolactam, vinylcarbazole, 2-vinylpyridine, and4-vinylpyridine); monomers containing 1,3-diketo groups (e.g.,acetoacetoxyethyl (meth)acrylate or diacetone acrylamide); monomerscontaining urea groups (e.g., ureidoethyl (meth)acrylate,acrylamidoglycolic acid, and methacrylamidoglycolate methyl ether);monoalkyl itaconates; monoalkyl maleates; hydrophobic branched estermonomers; monomers containing silyl groups (e.g., trimethoxysilylpropylmethacrylate), vinyl esters of branched mono-carboxylic acids having atotal of 8 to 12 carbon atoms in the acid residue moiety and 10 to 14total carbon atoms such as, vinyl 2-ethylhexanoate, vinyl neo-nonanoate,vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate andmixtures thereof, and copolymerizable surfactant monomers (e.g., thosesold under the trademark ADEKA REASOAP).

The polymer in the polymer binder can include one or more crosslinkingmonomers. Exemplary crosslinking monomers include N-alkylolamides ofα,β-monoethylenically unsaturated carboxylic acids having 3 to 10 carbonatoms and esters thereof with alcohols having 1 to 4 carbon atoms (e.g.,N-methylolacrylamide and N-methylolmethacrylamide); glycidyl(meth)acrylate; glyoxal based crosslinkers; monomers containing twovinyl radicals; monomers containing two vinylidene radicals; andmonomers containing two alkenyl radicals. Other crosslinking monomersinclude, for instance, diesters of dihydric alcohols withα,β-monoethylenically unsaturated monocarboxylic acids, of which in turnacrylic acid and methacrylic acid can be employed. Examples of suchmonomers containing two non-conjugated ethylenically unsaturated doublebonds can include alkylene glycol diacrylates and dimethacrylates, suchas ethylene glycol diacrylate, 1,3-butylene glycol diacrylate,1,4-butylene glycol diacrylate and propylene glycol diacrylate,divinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate,allyl acrylate, diallyl maleate, diallyl fumarate,methylenebisacrylamide, and mixtures thereof. In some embodiments, thepolymer can include from 0.01% to 5% by weight of the polymer, of thecrosslinking agent.

The polymer can have a glass-transition temperature (T_(g)), as measuredby differential scanning calorimetry (DSC) using the mid-pointtemperature as described, for example, in ASTM 3418/82, of from −90° C.to 100° C. In some embodiments, the polymer has a measured T_(g) of −90°C. or greater (for example, −80° C. or greater, −70° C. or greater, −60°C. or greater, −50° C. or greater, −40° C. or greater, −30° C. orgreater, −20° C. or greater, −10° C. or greater, 0° C. or greater, 10°C. or greater, 20° C. or greater, 30° C. or greater, 40° C. or greater,50° C. or greater, 60° C. or greater, 70° C. or greater, or 80° C. orgreater). In some cases, the polymer has a measured T_(g) of 100° C. orless (e.g., less than 100° C., 90° C. or less, 80° C. or less, 70° C. orless, 60° C. or less, 50° C. or less, 40° C. or less, 30° C. or less,25° C. or less, 20° C. or less, 10° C. or less, 0° C. or less, −10° C.or less, −20° C. or less, −25° C. or less, −30° C. or less, −35° C. orless, −40° C. or less, −45° C. or less, or −50° C. or less). In certainembodiments, the polymer has a measured T_(g) of from −90° C. to 90° C.,from −90° C. to 50° C., from −90° C. to 40° C., from −90° C. to 30° C.,from −90° C. to 25° C., −90° C. to 0° C., −90° C. to −10° C., from −80°C. to 25° C., from −80° C. to 10° C., from −80° C. to 0° C., from −80°C. to −10° C., from −60° C. to 30° C., from −60° C. to 25° C., from −60°C. to 0° C., from −60° C. to less than 0° C. or from −40° C. to lessthan 0° C.

The polymer binder can be formed from an aqueous dispersion, forexample, an aqueous latex dispersion. In some embodiments, the polymerbinder can include an aqueous latex dispersion of an acrylichomopolymer, a vinyl-aromatic-acrylic polymer, a vinyl-acrylic polymer,a vinyl chloride polymer, an acrylic-polyurethane hybrid polymer, avinyl alkanoate polymer, or a combination thereof.

Typical polymer binders used in coating compositions for applicationssuch as paints and inks are known in the art. For example, paint and inkformulations can include polymer binders commercially available underthe trade name ACRONAL® (available from BASF), JONCRYL® (available fromBASF), RHOPLEX® (available from The Dow Chemical Company), ROVACE®(available from The Dow Chemical Company), and EVOQUE® (available fromThe Dow Chemical Company).

Spheres

Porous Metal Oxide Spheres

As described herein, the coating compositions include a sphere such as amicrosphere. The term “sphere” as used herein refers to a particle,particularly, although not essentially, to a particle of circularcross-section, which has a largest dimension or mean diameter of atleast 1 μm, or from 1 μm to 100 μm. The sphere or microsphere can havereflective properties. The term “reflective” refers to an ability toscatter or reflect light of a particular wavelength from a surface. Thespheres described herein are capable of reflecting light of ultraviolet(UV), visible, or infrared (IR) wavelengths, or a combination thereof.Wavelengths in the UV region range from 10 nm to 400 nm, such as from100 nm to 400 nm or from 200 to 400 nm. Wavelengths in the visibleregion range from 400 nm to 800 nm, such as from 400 nm to 650 nm, orfrom 450 nm to 650 nm. Wavelengths in the infrared region range from 800nm to 10000 nm, such as from 800 nm to 5000 nm, from 800 nm to 2500 nm,or from 800 nm to 1000 nm. The spheres described herein are also capableof reflecting light having a wavelength of from 100 nm to 800 nm, suchas from 100 nm to 600 nm, from 200 nm to 800 nm, or from 200 to 400 nm,thus providing improved opacity. Spectroscopic methods for determiningreflectance values of a solid substance, including the spheres, are wellknown in the art and include, for example, pressing a neat powder of thesolid substance and placing the powder sample into a chamber of aspectrophotometer equipped with a reflectance spectroscopy accessory.

When an incident electromagnetic beam falls on a solid sample,reflection, transmission, and/or absorption can occur. The specificoptical effect that occurs is dependent on the sample's physicalcharacteristics and chemical composition. As such, the reflective andabsorptive properties of the spheres described herein can beindependently tuned across several different wavelength-scales bymodifying for example, the geometric properties and surface chemistry ofthe spheres. Specifically, the spheres described herein has areflectance tuning ability in the whole range of the UV, visible, and IRregions as further discussed herein.

In some examples, the spheres are derived from porous metal oxidespheres formed from metal oxide particles (e.g., nanoparticles). Theterm “metal oxide” refers to oxygen containing species of variousmetals, such as silicon, titanium, aluminum, zirconium, cerium, iron,zinc, indium, tin, chromium, antimony, bismuth, cobalt, gallium,lanthanum, molybdenum, neodymium, nickel, niobium, vanadium, orcombinations thereof. In specific examples, the metal oxide particlescan include a metal oxide selected from silica, titania, alumina,zirconia, ceria, iron oxides, zinc oxide, or combinations thereof. Morespecifically, the metal oxide particles can include SiO₂, TiO₂, Ti₂O₃,Al₂O₃, or Fe₂O₃.

To obtain reflectance over a wide spectral range, more than one type (ablend) of porous metal oxide sphere can be incorporated in the coatingcompositions. A combination of two porous metal oxide spheres canincrease the spectral range over which reflectance is observed.

Preferably, the porous metal oxide spheres exhibit an ability todisperse well into the coating compositions and thus uniformly coat asurface. In particular, the porous metal oxide spheres are preferablycompatible with all types of solvent and coating systems such asacrylics and styrene-acrylic systems.

The porous metal oxide spheres can include one or more metal oxides inan amount of 60% by weight or greater. For example, the porous metaloxide spheres can include one or more metal oxides in an amount of 65%or greater, 70% or greater, 75% or greater, 80% or greater, 85% orgreater, 90% or greater, 95% or greater, 97% or greater, 98% or greater,99% or greater, or up to 100% by weight of the porous metal oxidesphere. In some embodiments, the porous metal oxide spheres can includeone or more metal oxides in an amount of 65% up to 100% by weight (e.g.,from 65% to 99%, from 70% to 99%, from 80% to 99%, from 90% to 99%, from70% to 90%, or from 75% to 95% by weight), based on the weight of theporous metal oxide sphere.

As the porous metal oxide spheres are prepared with the use of apolymeric sacrificial particles which is removed for instance viacalcination, the porous metal oxide spheres can include a minor amountof carbon containing material produced in situ from polymerdecomposition. In some embodiments, the porous metal oxide spheres caninclude carbon black or a hydrocarbon material. Carbon black pigmentshas a high IR absorption and are conventionally used in coatings such aspaints and stains. In some embodiments of the coating compositionsdisclosed herein, controlled calcination can be employed to producecarbon black in situ in the porous metal oxide spheres. The porous metaloxide spheres can include materials other than the metal oxides (such ascarbon black) in an amount of less than 35% by weight, (e.g., less than20%, less than 15%, less than 10%, less than 5%, less than 2%, less than1%, from 0% to 35%, from 0.1% to 20%, from 0.1% to 10%, from 0.1% to 5%,or from 0.1% to 2% by weight), based on the weight of the porous metaloxide sphere.

The porous metal oxide spheres are porous. The term “porous” as usedherein refers to one or more interconnected or non-interconnected pores,voids, spaces, or interstices that allow air or liquid to pass through.In general, porosity, void diameter, and particle size diameter ofspherical spheres can be tuned to enable the coating composition toscatter incident light over the whole range of the UV, visible, and IRregions.

The term “porosity” as used herein refers to a measure of the emptyspaces (or voids or pores) in the spheres and is a ratio of the volumeof voids to total volume of the mass of the spheres between 0 and 1, oras a percentage between 0 and 100%. Average porosity of a sphere meansthe total pore volume, as a fraction of the volume of the entire sphere.Porosity can be measured by means known in the art such as by mercuryporosimetry analysis. The porous metal oxide spheres can contain uniformor non-uniform pore diameters, a result of the polymer particles beingspherical and monodisperse or polydisperse.

The porous metal oxide spheres may contain a high degree of porosity dueto removal of the sacrificial polymer particles described herein. Insome embodiments, the porous metal oxide spheres can have an averageporosity of 0.10 or greater. For example, the porous metal oxide spherescan have an average porosity of 0.15 or greater, 0.18 or greater, 0.20or greater, 0.25 or greater, 0.28 or greater, 0.30 or greater, 0.35 orgreater, 0.40 or greater, 0.45 or greater, 0.50 or greater, 0.55 orgreater, 0.60 or greater, 0.65 or greater, 0.70 or greater, 0.75 orgreater, 0.80 or greater, 0.85 or greater, or up to 0.90. In certainembodiments, the porous metal oxide spheres can have an average porosityof 0.90 or less, 0.85 or less, 0.80 or less, 0.75 or less, 0.70 or less,0.65 or less, 0.60 or less, 0.55 or less, 0.50 or less, 0.45 or less,0.40 or less, 0.35 or less, 0.30 or less, 0.25 or less, 0.20 or less, or0.15 or less. The porous metal oxide spheres can have a porosity fromany of the minimum values to any of the maximum values described aboveof the porous metal oxide spheres. For example, the porous metal oxidespheres can have an average porosity of from 0.10 to 0.90, from 0.10 to0.80, from 0.15 to 0.80, from 0.20 to 0.70, from 0.20 to 0.60, from 0.45to 0.70, from 0.40 to 0.65, from 0.45 to 0.65, or from 0.45 to 0.55.

The porosity of the porous metal oxide spheres can be such that thespheres have a solid core (center) where the porosity is in generaltowards the exterior surface of the sphere. In other embodiments, theporous metal oxide spheres can have a hollow core where a major portionof the porosity is towards the interior of the spheres. In otherembodiments, the porosity can be distributed throughout the volume ofthe spheres. In further embodiments, the porosity can exist as agradient, with higher porosity towards the exterior surface of thespheres and lower or no porosity (solid) towards the center; or withlower porosity towards the exterior surface and with higher or completeporosity (hollow) towards the center.

As discussed herein, there also exists a relationship between the poresize/pore diameter and the reflectance properties of the spheres withrespect to the wavelength. The average pore size (or pore diameter) ofthe spheres derived from the porous metal oxide spheres can vary,depending on the size of the sacrificial polymer particles used tocreate the pore size (although some “shrinkage” or compaction may occurupon polymer removal, providing pore sizes somewhat smaller than theoriginal polymer particle size). As described herein, sphericalmonodispersed sacrificial polymer particles (e.g., nanoparticles) can beemployed to create a substantially uniform and unimodal distribution ofpore sizes. In other cases, a multimodal distribution of sacrificialpolymer particles (e.g., nanoparticles) can be employed to create amultimodal distribution, such as a bimodal distribution, of pore sizes.In general, however, the pore size of the spheres derived from theporous spheres is nano- or micro-scaled, preferably from about 50 nm toabout 10000 nm.

In some embodiments, the porous metal oxide sphere can have an averagepore diameter of 50 nm or greater, 75 nm or greater, 100 nm or greater,150 nm or greater, 200 nm or greater, 250 nm or greater, 300 nm orgreater, 350 nm or greater, 400 nm or greater, 450 nm or greater, 500 nmor greater, 550 nm or greater, 600 nm or greater, 650 nm or greater, 700nm or greater, 750 nm or greater, 800 nm or greater, 850 nm or greater,1 μm or greater, 1.5 μm or greater, 2 μm or greater, 2.5 μm or greater,3 μm or greater, 3.5 μm or greater, 4 μm or greater, 4.5 μm or greater,5 μm or greater, 5.5 μm or greater, 6 μm or greater, 7 μm or greater,7.5 μm or greater, 8 μm or greater, 8.5 μm or greater, 9 μm or greater,9.5 μm or greater, or up to 10 μm. In some embodiments, the porous metaloxide spheres can have an average pore diameter of 10 μm or less, 9.5 μmor less, 9 μm or less, 8.5 μm or less, 8 μm or less, 7.5 μm or less, 7μm or less, 6.5 μm or less, 6 μm or less, 5.5 μm or less, 5 μm or less,4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, 2.5 μm orless, 2 μm or less, 1.5 μm or less, 1 μm or less, 950 nm or less, 800 nmor less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less,550 nm or less, 500 nm or less, 450 nm or less, 400 nm or less, 350 nmor less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less,or 100 nm or less. The porous metal oxide spheres can have an averagepore diameter from any of the minimum values to any of the maximumvalues described above of the porous metal oxide spheres. For example,the porous metal oxide spheres can have an average pore diameter of from50 nm to 10 μm, from 50 nm to 5 μm, from 100 nm to 10 μm, from 100 nm to5 μm, from 100 nm to 2.5 μm, from 100 nm to 1 μm, from 800 nm to 10 μm,from 800 nm to 5 μm, from 800 nm to 2.5 μm, from 800 nm to 1 μm, from400 nm to 800 nm, from 400 nm to 700 nm, from 200 nm to 400 nm, or from100 nm to 400 nm. The average pore diameter of the porous metal oxidespheres can be determined by electron microscopy.

The pore size and pore distribution of the porous metal oxide spherescan be ordered (periodic structures) or disordered (random structures).Angle-dependent reflectance may be achieved in the coatings using theporous metal oxide spheres having an ordered pore size distribution. Anordered pore size and pore distribution may be achieved for example withthe use of monodisperse sacrificial polymer particles during preparationof the porous metal oxide spheres or when a step of drying the liquiddroplets to provide the porous metal oxide spheres is performed slowly,allowing the metal oxide and sacrificial polymer particles to becomeordered. Angle-independent reflectance may be achieved in the coatingsusing porous metal oxide spheres having a disordered pore size and poredistribution. A disordered pore size and pore distribution may beachieved for example when a step of drying the liquid droplets isperformed quickly, not allowing the metal oxide and sacrificial polymerparticles to become ordered.

Polymer Spheres

In alternate embodiments, the spheres (e.g., microspheres) can beorganic and include polymer spheres formed from a multimodaldistribution of polymer particles (e.g., nanoparticles). Like the porousmetal oxide spheres, the reflective and absorptive properties of thepolymer spheres can be independently tuned across the whole range of theUV, visible, and IR regions by modifying for example, their geometricproperties and surface chemistry as discussed herein. The polymerspheres can include a polymer selected from poly(meth)acrylic acid,poly(meth)acrylates, polystyrenes, polyacrylamides, polyethylene,polypropylene, polylactic acid, polyacrylonitrile, derivatives thereof,salts thereof, blends thereof, or copolymers thereof. In some cases, thepolymer spheres can include copolymers such as polystyrene/acrylic acid,polystyrene/poly(ethylene glycol) methacrylate or polystyrene/styrenesulfonate.

As described herein the polymer spheres can be formed from polymerparticles (e.g., nanoparticles). The packing of the polymer particles inthe polymer spheres can be ordered (periodic structures) or disordered(random structures). The polymer particles can have an average diameterof 50 nm or greater, 75 nm or greater, 100 nm or greater, 120 nm orgreater, 150 nm or greater, 170 nm or greater, 200 nm or greater, 250 nmor greater, 300 nm or greater, 350 nm or greater, 400 nm or greater, 450nm or greater, 500 nm or greater, 550 nm or greater, 600 nm or greater,650 nm or greater, 700 nm or greater, 750 nm or greater, 800 nm orgreater, 850 nm or greater, 900 nm or greater, 950 nm or greater, or1000 nm or greater. For example, the polymer particles can have anaverage diameter of from 50 nm to 1 μm, from 50 nm to 750 nm, from 100nm to 1 μm, from 100 nm to 750 nm, from 100 nm to 500 nm, from 100 nm to400 nm, or from 200 nm to 400 nm.

As described herein, the polymer spheres can be formed from a multimodaldistribution of polymer particles with respect to size, for example,bimodal, trimodal, quadrimodal, and such the like. In some embodiment, afirst population of polymer particles in the polymer spheres can have anaverage diameter of from 50 nm to 750 nm, from 100 nm to 750 nm, from100 nm to 500 nm, from 100 nm to 400 nm, or from 200 nm to 400 nm. Insome embodiment, a second population of polymer particles in the polymerspheres can have an average diameter of from 500 nm to 1 μm, from 500 nmto 750 nm, from 600 nm to 900 nm, or from 750 nm to 1 μm.

The polymer spheres can be formed from a multimodal distribution ofpolymer particles, for example, bimodal, trimodal, quadrimodal, and suchthe like, with respect to the composition of the polymer particles. Forexample, the polymers of each population of polymer particles can bedifferent. In alternate embodiments, the polymers of each population ofpolymer particles can be the same.

The spheres derived from the porous metal oxide spheres or the polymerspheres can have an average diameter of 1 μm or greater, 1.5 μm orgreater, 2 μm or greater, 2.5 μm or greater, 3 μm or greater, 3.5 μm orgreater, 4 μm or greater, 4.5 μm or greater, 5 μm or greater, 5.5 μm orgreater, 6 μm or greater, 7 μm or greater, 7.5 μm or greater, 8 μm orgreater, 8.5 μm or greater, 9 μm or greater, 9.5 μm or greater, 10 μm orgreater, 15 μm or greater, 20 μm or greater, 30 μm or greater, 40 μm orgreater, 50 μm or greater, 60 μm or greater, 70 μm or greater, 80 μm orgreater, 90 μm or greater, or 100 μm or greater. In some embodiments,the spheres derived from the porous metal oxide spheres or the polymerspheres can have an average diameter of 100 μm or less, 90 μm or less,80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm orless, 30 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, 9.5 μmor less, 9 μm or less, 8.5 μm or less, 8 μm or less, 7.5 μm or less, 7μm or less, 6.5 μm or less, 6 μm or less, 5.5 μm or less, 5 μm or less,4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, 2.5 μm orless, 2 μm or less, 1.5 μm or less, or 1 μm or less. The spheres derivedfrom the porous metal oxide spheres or the polymer spheres can have anaverage diameter from any of the minimum values to any of the maximumvalues described above of the spheres. For example, the spheres derivedfrom the porous metal oxide spheres or the polymer spheres can have anaverage diameter of from 1 μm to 100 μm, from 5 μm to 100 μm, from 10 μmto 50 μm, from 1 μm to 10 μm, from 1 μm to 5 μm, or from 1 μm to 3 μm.The average particle diameter (also referred to herein as averageparticle size) of the spheres derived from the porous metal oxidespheres or the polymer spheres can be determined by scanning electronmicroscopy (SEM) or transmission electron microscopy (TEM). Averageparticle size is synonymous with D50, meaning half of the populationresides above this point, and half below.

As discussed herein, the UV, visible, or IR reflective properties andefficiencies of the coating compositions can be controlled by thephysical and chemical properties of the spheres. To find the optimumreflectance characteristics of the coating compositions, the sphereproperties can be tuned. In particular, the spheres can be made highlyreflective because their geometry, the number of pores within a givenpigment that are active, and degree of order can be preciselycontrolled. In addition to their reflective properties, the spheres canexhibit improved hiding capabilities. These features of the spheresprovide the capability of producing in/proved reflectance in coatingcompositions not previously attainable with conventional pigments, whichlacked the tuning capabilities of the spheres. When the optimizationparameters are maximized, the resultant coatings can have highreflectance in the UV, visible, or IR region, or a combination thereof

Coating Compositions

Provided herein are coating compositions comprising a polymer binder anda sphere (e.g., a microsphere) as described herein. The coatingcompositions when dried, can exhibit UV reflectance, such as within awavelength from 100 nm to 400 nm; visible light reflectance such aswithin a wavelength of from 400 to 800 nm; IR reflectance such as withina wavelength from 800 nm to 10 μm; reflectance within a wavelength offrom 100 to 800 nm for providing improved opacity; or a combinationthereof. The reflectance of the coatings with respect to the wavelengthand intensity can be dependent on the physical characteristics (such asparticle size, porosity, and pore size) as well as the chemicalcharacteristics of the spheres, as discussed herein.

In some embodiments, the coating composition is a UV reflectivecomposition. In some examples, the UV reflective composition can includeporous metal oxide spheres having an average diameter of from 1 μm to 10μm (e.g., from 1 μm to 10 μm, from 2 μm to 10 μm, from 1 μm to 5 μm,from 0.5 μm to 3 μm, from 1 μm to 3 μm, from 1 μm to 2.5 μm, or from 1.5μm to 3 μm); an average porosity of 0.20 or greater (e.g., from 0.20 to0.90, from 0.20 to 0.80, from 0.20 to 0.70, from 0.30 to 0.65, from 0.40to 0.65, from 0.45 to 0.65, or from 0.45 to 0.55); and an average porediameter of from 50 nm to 400 nm (e.g., from 100 nm to 400 nm, from 50nm to 350 nm, from 50 nm to 300 nm, from 50 nm to 250 nm, from 50 nm to200 nm, from 150 nm to 400 nm, from 200 nm to 400 nm, or from 100 nm to350 nm). In other examples, the UV reflective composition can be a clearcoating compositions comprising a polymer selected from acrylichomopolymers, styrene-acrylic-based copolymers, styrene-butadiene-basedcopolymers, styrene-butadiene-styrene copolymers, vinyl acryliccopolymers, ethylene vinyl acetate copolymers, polychloroprene, blendsthereof, or copolymers thereof; and a sphere comprising porous metaloxide spheres formed from metal oxide particles, wherein the sphere hasan average particle size diameter of from 1 micron to 10 microns, from 1micron to 5 microns, or from 1 micron to 3 microns, and wherein theclear coating composition when dried exhibits a UV reflectance at awavelength range from 100 nm to 400 nm. The UV reflective compositionscan further comprise one or more UV absorbers, such as selected from ahydroxy-phenyl-benzotriaziole, a hydroxy-phenyl-triazine, ahydroxyl-benzophenone, an oxanilide, a cyanoacrylate, a malonate and amixture thereof.

In some embodiments, the coating composition is a composition havingimproved opacity. In some examples, the composition having improvedopacity can include porous metal oxide spheres having an averagediameter of from 0.5 μm to 100 μm (e.g., from 1 μm to 100 μm, from 1 μmto 50 μm, from 1 μm to 30 μm, from 1 μm to 20 μm, from 1 μm to 10 μm,from 1 μm to 8 μm, or from 2 μm to 7 μm); an average porosity of 0.20 orgreater (e.g., from 0.20 to 0.90, from 0.20 to 0.80, from 0.20 to 0.70,from 0.30 to 0.65, from 0.40 to 0.65, from 0.45 to 0.65, or from 0.45 to0.55); and an average pore diameter of from 50 nm to 800 nm (e.g., from50 nm to 600 nm, from 50 nm to 400 nm, from 50 nm to 200 nm, from 100 nmto 800 nm, from 100 nm to 600 nm, from 100 nm to 400 nm, from 200 nm to800 nm, from 200 nm to 400 nm, from 250 nm to 400 nm, or from 200 nm to350 nm). In other examples, the coating compositions exhibiting improvedopacity are paint compositions comprising a polymer selected fromacrylic homopolymers, styrene-acrylic-based copolymers,styrene-butadiene-based copolymers, styrene-butadiene-styrenecopolymers, vinyl acrylic copolymers, ethylene vinyl acetate copolymers,polychloroprene, blends thereof, or copolymers thereof; and a sphereselected from porous metal oxide spheres formed from metal oxideparticles, polymer spheres formed from a multimodal distribution ofpolymer particles, or a mixture thereof, wherein the sphere has anaverage particle size diameter of 100 microns or less, 50 microns orless, more 10 microns or less, or from 1 micron to 10 microns, and anaverage porosity of from or from 0.40 to 0.65, or from 0.45 to 0.55.

In some embodiments, the coating composition is an IR reflectivecomposition. In some examples, the IR reflective composition can includeporous metal oxide spheres having an average diameter of from 5 μm to100 μm (e.g., from 5 μm to 75 μm, from 5 μm to 50 μm, or from 10 μm to30 μm); an average porosity of 0.20 or greater (e.g., from 0.20 to 0.90,from 0.20 to 0.80, from 0.20 to 0.70, from 0.30 to 0.65, from 0.40 to0.65, from 0.45 to 0.65, or from 0.45 to 0.55); and an average porediameter of from 400 nm to 10 μm (e.g., from 400 nm to 5 μm, from 400 nmto 2.5 μm, from 400 nm to 1 μm, from 800 nm to 10 μm, from 800 nm to 5μm, from 800 nm to 2.5 μm, from 800 nm to 1.5 μm, or from 800 nm to 1μm). In some examples, the IR reflective composition can include porousmetal oxide spheres having an average diameter of greater than about 50μm (e.g., from 80 μm to 100 μm or about 100 μm); an average porosity of0.20 or greater (e.g., from 0.20 to 0.90, from 0.20 to 0.80, from 0.20to 0.70, from 0.30 to 0.65, from 0.40 to 0.65, from 0.45 to 0.65, orfrom 0.45 to 0.55); and an average pore diameter of from 400 nm to 10 μm(e.g., from 400 nm to 5 μm, from 400 nm to 2.5 μm, from 400 nm to 1 μm,from 800 nm to 10 μm, from 800 nm to 5 μm, from 800 nm to 2.5 μm, from800 nm to 1.5 μm, or from 800 nm to 1 μm). In some examples, the IRreflective composition can include porous metal oxide spheres having anaverage diameter of less than about 5 μm (e.g., about 5 μm); an averageporosity of 0.20 or greater (e.g., from 0.20 to 0.90, from 0.20 to 0.80,from 0.20 to 0.70, from 0.30 to 0.65, from 0.40 to 0.65, from 0.45 to0.65, or from 0.45 to 0.55); and an average pore diameter of from 400 nmto 1 μm (e.g., from 400 nm to 900 nm, from 400 to 800 nm, from 400 to750 nm, or from 400 to 700 nm).

In other examples, the IR reflective coating composition comprises apolymer selected from acrylic homopolymers, styrene-acrylic-basedcopolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, alkyd resin, polyesterresins, polyurethane resins, silicone resins, petroleum resins, epoxyresins, blends thereof, or copolymers thereof; and a sphere selectedfrom porous metal oxide spheres formed from metal oxide particles (e.g.,nanoparticles), polymer spheres formed from a multimodal distribution ofpolymer particles (e.g., nanoparticles), or a mixture thereof, whereinthe sphere has an average particle size diameter of 5 microns or greateror from 5 microns to 100 microns and an average porosity of from or from0.40 to 0.65 or from 0.45 to 0.55, and wherein the coating compositionwhen dried exhibits an IR reflectance at a wavelength range from 800 nmto 10 microns, from 800 nm to 2.5 microns, or from 800 nm to 1 micron.

The coating compositions can include the sphere in an amount fromgreater than 0% by weight to 99.9% by weight (e.g., 0.1% or greater,0.5% or greater, 1% or greater, 2.5% or greater, 5% or greater, 7% orgreater, 10% or greater, 12.5% or greater, 15% or greater, 20% orgreater, 22% or greater, 25% or greater, 30% or greater, 35% or greater,40% or greater, 45% or greater, 50% or greater, 55% or greater, 60% orgreater, 65% or greater, 70% or greater, 75% or greater, 80% or greater,85% or greater, 90% or greater, 95% or greater, or up to 99.9% byweight), based on the total dry weight of the coating composition. Thecoating composition can include the sphere in an amount of 99.9% byweight or less, 99% by weight or less, 98% by weight or less, 95% byweight or less, 90% by weight or less, 85% by weight or less, 80% byweight or less, 75% by weight or less, 70% by weight or less, 65% byweight or less, 60% by weight or less, 55% by weight or less, 50% byweight or less, 45% by weight or less, 40% by weight or less, 35% byweight or less, 30% by weight or less, 25% by weight or less, 20% byweight or less, 15% by weight or less, 10% by weight or less, 8% byweight or less, 7% by weight or less, 6% by weight or 5% by weight orless, 4% by weight or less, 3% by weight or less, 2% by weight or less,or 1% by weight or less), based on the total dry weight of the coatingcomposition. The coating composition can include the sphere in an amountfrom 0.1% by weight to 99.9% by weight, from 0.5% by weight to 99% byweight, from 0.5% by weight to 95% by weight, from 1% by weight to 90%by weight, from 5% by weight to 99.9% by weight, from 10% by weight to90% by weight, from 15% by weight to 85% by weight, based on the totaldry weight of the coating composition.

The coating composition can include the polymer binder in an amount fromgreater than 0% by weight to 99.9% by weight (e.g., 0.1% or greater,0.5% or greater, 1% or greater, 2.5% or greater, 5% or greater, 7% orgreater, 10% or greater, 12.5% or greater, 15% or greater, 20% orgreater, 22% or greater, 25% or greater, 30% or greater, 35% or greater,40% or greater, 45% or greater, 50% or greater, 55% or greater, 60% orgreater, 65% or greater, 70% or greater, 75% or greater, 80% or greater,85% or greater, 90% or greater, 95% or greater, or up to 99.9% byweight), based on the total dry weight of the coating composition. Thecoating composition can include the polymer binder in an amount of 99.9%by weight or less, 99% by weight or less, 98% by weight or less, 95% byweight or less, 90% by weight or less, 85% by weight or less, 80% byweight or less, 75% by weight or less, 70% by weight or less, 65% byweight or less, 60% by weight or less, 55% by weight or less, 50% byweight or less, 45% by weight or less, 40% by weight or less, 35% byweight or less, 30% by weight or less, 25% by weight or less, 20% byweight or less, 15% by weight or less, 10% by weight or less, 8% byweight or less, 7% by weight or less, 6% by weight or 5% by weight orless, 4% by weight or less, 3% by weight or less, 2% by weight or less,or 1% by weight or less), based on the total dry weight of the coatingcomposition. The coating composition can include the polymer binder inan amount from 0.1% by weight to 99.9% by weight, from 0.5% by weight to99% by weight, from 0.5% by weight to 95% by weight, from 1% by weightto 90% by weight, from 5% by weight to 99.9% by weight, from 10% byweight to 90% by weight, from 15% by weight to 85% by weight, based onthe total dry weight of the coating composition.

The coating compositions can include additional components. For example,the coating compositions can include an additive such as a pigmentdispersant, an inorganic or organic filler, an additional pigment, apigment extender, a thickener, a defoamer, a surfactant, a biocide, anadhesion enhancer, a coalescing agent, a film forming aid, a flameretardant, a stabilizer, a curing agent, a flow agent, a leveling agent,a light stabilizer, a wetting agent, a hardener, a tackifier, ananti-settling aid, a texture-improving agent, an antiflocculating agent,or a combination thereof. The additive can be added to impart certainproperties to the coating compositions such as thickness, texture,handling, fluidity, smoothness, whiteness, increased density or weight,decreased porosity, increased opacity, flatness, glossiness, decreasedblocking resistance, barrier properties, and the like.

In some embodiments, the coating compositions include a mineral fillerand/or a pigment. When present, the mineral filler and/or pigment can beselected from TiO₂ (in both anatase and rutile forms), clay (aluminumsilicate), CaCO₃ (in both ground and precipitated forms), aluminumtrihydrate, fly ash, or aluminum oxide, silicon dioxide, magnesiumoxide, talc (magnesium silicate), barytes (barium sulfate), zinc oxide,zinc sulfite, sodium oxide, potassium oxide, and mixtures thereof.Examples of commercially available titanium dioxide pigments are KRONOS®2101, KRONOS® 2310, available from Kronos WorldWide, Inc., TI-PURE®R-900, available from DuPont, or TIONA® AT1 commercially available fromMillennium Inorganic Chemicals. Titanium dioxide is also available inconcentrated dispersion form. An example of a titanium dioxidedispersion is KRONOS® 4311, also available from Kronos Worldwide, Inc.Suitable pigment blends of mineral fillers are sold under the marksMINEX® (oxides of silicon, aluminum, sodium and potassium commerciallyavailable from Unimin Specialty Minerals), CELITE® (aluminum oxide andsilicon dioxide commercially available from Celite Company), andATOMITE® (commercially available from Imerys Performance Minerals).Exemplary fillers also include clays such as attapulgite clays andkaolin clays including those sold under the ATTAGEL® and ANSILEX® marks(commercially available from BASF Corporation). Additional fillersinclude nepheline syenite, (25% nepheline, 55% sodium feldspar, and 20%potassium feldspar), feldspar (an aluminosilicate), diatomaceous earth,calcined diatomaceous earth, talc (hydrated magnesium silicate),aluminosilicates, silica (silicon dioxide), alumina (aluminum oxide),mica (hydrous aluminum potassium silicate), pyrophyllite (aluminumsilicate hydroxide), perlite, baryte (barium sulfate), wollastonite(calcium metasilicate), and combinations thereof. More preferably, thecoating compositions can include TiO₂, CaCO₃, and/or a clay. In someembodiments, the coating composition does not include a pigment and/or amineral filler other than the sphere.

When present, the mineral filler and/or pigment can comprise particleshaving a number average particle size of 50 microns or less (e.g., 45microns or less, 40 microns or less, 35 microns or less, 30 microns orless, 25 microns or less, 20 microns or less, 18 microns or less, 15microns or less, 10 microns or less, 8 microns or less, or 5 microns orless). In some embodiments, the mineral filler and/or pigment can have anumber average particle size of 10 microns or greater, 12 microns orgreater, 15 microns or greater, 20 microns or greater, 25 microns orgreater, 30 microns or greater, 35 microns or greater, 40 microns orgreater, or 45 microns or greater. In some embodiments, the mineralfiller and/or pigment can have a number average particle size of from 10microns to 50 microns, from 10 microns to 35 microns, or from 10 micronsto 25 microns.

The mineral filler and/or pigment, if present, can be present in anamount of 1% by weight or greater, based on the total weight of thecoating composition. For example, the mineral filler and/or pigment canbe present in an amount of from 1% by weight to 85% by weight, from 10%by weight to 85% by weight, from 15% by weight to 75% by weight or from15% by weight to 65% by weight, based on the total weight of the coatingcomposition. The coating compositions can include spheres and acombination of mineral fillers and pigments in weight ratios of 90:10,80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80 or 10:90. In some cases,the coating composition can include from 0.1% by weight to 90% by weight(e.g., from 1% by weight to 60% by weight, from 1% by weight to 55% byweight, from 1% by weight to 50% by weight, or from 5% by weight to 50%by weight) of spheres and/or mineral fillers and/or pigments.

Examples of suitable pigment dispersing agents for use in the coatingcompositions are polyacid dispersants and hydrophobic copolymerdispersants. Polyacid dispersants are typically polycarboxylic acids,such as polyacrylic acid or polymethacrylic acid, which are partially orcompletely in the form of their ammonium, alkali metal, alkaline earthmetal, ammonium, or lower alkyl quaternary ammonium salts. Hydrophobiccopolymer dispersants include copolymers of acrylic acid, methacrylicacid, or maleic acid with hydrophobic monomers. In certain embodiments,the composition includes a polyacrylic acid-type dispersing agent, suchas Pigment Disperser N, commercially available from BASF SE.

Examples of suitable thickeners include hydrophobically modifiedethylene oxide urethane (HEUR) polymers, hydrophobically modified alkalisoluble emulsion (HASE) polymers, hydrophobically modified hydroxyethylcelluloses (HMHECs), hydrophobically modified polyacrylamide, andcombinations thereof. HEUR polymers are linear reaction products ofdiisocyanates with polyethylene oxide end-capped with hydrophobichydrocarbon groups. HASE polymers are homopolymers of (meth)acrylicacid, or copolymers of (meth)acrylic acid, (meth)acrylate esters, ormaleic acid modified with hydrophobic vinyl monomers. HMHECs includehydroxyethyl cellulose modified with hydrophobic alkyl chains.Hydrophobically modified polyacrylamides include copolymers ofacrylamide with acrylamide modified with hydrophobic alkyl chains(N-alkyl acrylamide). In certain embodiments, the coating compositionincludes a hydrophobically modified hydroxyethyl cellulose thickener.Other suitable thickeners that can be used in the coating compositionscan include acrylic copolymer dispersions sold under the STEROCOLL™ andLATEKOLL™ trademarks from BASF Corporation, Florham Park, N.J.;urethanes thickeners sold under the RHEOVIS™ trademark (e.g., Rheovis PU1214); hydroxyethyl cellulose; guar gum; carrageenan; xanthan; acetan;konjac; mannan; xyloglucan; and mixtures thereof. The thickeners can beadded to the composition compositions as an aqueous dispersion oremulsion, or as a solid powder.

Suitable coalescing aids, which aid in film formation during drying,include ethylene glycol monomethyl ether, ethylene glycol monobutylether, ethylene glycol monoethyl ether acetate, ethylene glycolmonobutyl ether acetate, diethylene glycol monobutyl ether, diethyleneglycol monoethyl ether acetate, dipropylene glycol monomethyl ether,propylene glycol n-butyl ether, dipropylene glycol n-butyl ether,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, or combinationsthereof. In some embodiments, the coating compositions can include oneor more coalescing aids such as propylene glycol n-butyl ether and/ordipropylene glycol n-butyl ether. The coalescing aids, if present, canbe present in an amount of from greater than 0% to 30%, based on the dryweight of the polymer binder. For example, the coalescing aid can bepresent in an amount of from 10% to 30%, from 15% to 30% or from 15% to25%, based on the dry weight of the polymer binder. In some embodiments,the coalescing aid can be included in coating compositions comprising ahigh Tg polymer binder (that is a polymer having a Tg greater thanambient temperature (e.g., 20° C.)). In these embodiments, thecoalescing aid can be present in an effective amount to provide coatingcompositions having a Tg less than ambient temperature (e.g., 20° C.).In some embodiments, the compositions do not include a coalescing aid.

Defoamers serve to minimize frothing during mixing and/or application ofthe coating compositions. Suitable defoamers include organic defoamerssuch as mineral oils, silicone oils, and silica-based defoamers.Exemplary silicone oils include polysiloxanes, polydimethylsiloxanes,polyether modified polysiloxanes, or combinations thereof. Exemplarydefoamers include BYK®-035, available from BYK USA Inc., the TEGO®series of defoamers, available from Evonik Industries, the DREWPLUS®series of defoamers, available from Ashland Inc., and FOAMASTER® NXZ,available from BASF Corporation.

Plasticizers can be added to the coating compositions to reduce theglass transition temperature (T_(g)) of the compositions below that ofthe drying temperature to allow for good film formation. Suitableplasticizers include diethylene glycol dibenzoate, dipropylene glycoldibenzoate, tripropylene glycol dibenzoate, butyl benzyl phthalate, or acombination thereof. Exemplary plasticizers include phthalate-basedplasticizers. The plasticizer can be present in an amount of from 1% to15%, based on the dry weight of the polymer binder. For example, theplasticizer can be present in an amount of from 5% to 15% or from 7% to15%, based on the dry weight of the polymer binder. In some embodiments,the plasticizer can be present in an effective amount to provide coatingcompositions having a Tg less than ambient temperature (e.g., 20° C.).In some embodiments, the compositions do not include a plasticizer.

Suitable surfactants include nonionic surfactants and anionicsurfactants. Examples of nonionic surfactants are alkylphenoxypolyethoxyethanols having alkyl groups of about 7 to about 18 carbonatoms and having from about 6 to about 60 oxyethylene units; ethyleneoxide derivatives of long chain carboxylic acids; analogous ethyleneoxide condensates of long chain alcohols, and combinations thereof.Exemplary anionic surfactants include ammonium, alkali metal, alkalineearth metal, and lower alkyl quaternary ammonium salts ofsulfosuccinates, higher fatty alcohol sulfates, aryl sulfonates, alkylsulfonates, alkylaryl sulfonates, and combinations thereof. In certainembodiments, the composition comprises a nonionic alkylpolyethyleneglycol surfactant, such as LUTENSOL® TDA 8 or LUTENSOL® AT-18,commercially available from BASF SE. In certain embodiments, thecomposition comprises an anionic alkyl ether sulfate surfactant, such asDISPONIL® FES 77, commercially available from BASF SE. In certainembodiments, the composition comprises an anionic diphenyl oxidedisulfonate surfactant, such as CALFAX® DB-45, commercially availablefrom Pilot Chemical.

Examples of suitable pH modifying agents include bases such as sodiumhydroxide, potassium hydroxide, amino alcohols, monoethanolamine (MEA),diethanolamine (DEA), 2-(2-aminoethoxy)ethanol, diisopropanolamine(DIPA), 1-amino-2-propanol (AMP), ammonia, and combinations thereof. Insome embodiments, the compositions do not include an ammonia-based pHmodifier. The pH of the dispersion can be greater than 7. For example,the pH can be 7.5 or greater, 8.0 or greater, 8.5 of greater, or 9.0 orgreater.

Suitable biocides can be incorporated to inhibit the growth of bacteriaand other microbes in the coating composition during storage. Exemplarybiocides include 2-[(hydroxymethyl)amino]ethanol, 2-[(hydroxymethyl)amino]2-methyl-1-propanol, o-phenylphenol, sodium salt,1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one (MIT),5-chloro2-methyland-4-isothiazolin-3-one (CIT),2-octyl-4-isothiazolin-3-one (OIT),4,5-dichloro-2-n-octyl-3-isothiazolone, as well as acceptable salts andcombinations thereof. Suitable biocides also include biocides thatinhibit the growth of mold, mildew, and spores thereof in the coating.Examples of mildewcides include 2-(thiocyanomethylthio)-benzothiazole,3-iodo-2-propynyl butyl carbamate, 2,4,5,6-tetrachloroisophthalonitrile,2-(4-thiazolyl)benzimidazole, 2-N-octyl4-isothiazolin-3-one,diiodomethyl p-tolyl sulfone, as well as acceptable salts andcombinations thereof. In certain embodiments, the coating compositioncontains 1,2-benzisothiazolin-3-one or a salt thereof. Biocides of thistype include PROXEL® BD20, commercially available from Arch Chemicals,Inc. The biocide can alternatively be applied as a film to the coatingand a commercially available film-forming biocide is Zinc Omadine®commercially available from Arch Chemicals, Inc.

Exemplary co-solvents and humectants include ethylene glycol, propyleneglycol, diethylene glycol, and combinations thereof. Exemplarydispersants can include sodium polyacrylates in aqueous solution such asthose sold under the DARVAN trademark by R.T. Vanderbilt Co., Norwalk,Conn.

The coating compositions can be used for several applications, includingin architectural coatings such as an architectural paint, industrialcoatings, or inks, which are further discussed herein. In some examples,the coating compositions can be provided as a paint, such as an aqueousbased paint, a semi-gloss paint, or a high gloss paint. Generally,coatings are formed by applying the coating composition as describedherein to a surface, and allowing the coating to dry (that is, removalof 95% by weight or greater, such as from 95% to 99% by weight ofvolatiles) to form a dried coating, such as a film. The surface can be,for example, wood, glass, metal, wood, plastic, asphalt, concrete,ceramic material or another coating layer applied on such a surface.Specific surfaces include wall, PVC pipe, brick, mortar, carpet,granule, pavement, ceiling tile, sport surface, exterior insulation andfinish system (EIFS), polyurethane foam surface, polyolefin surface,ethylene-propylene diene monomer (EPDM) surface, roof, vinyl, andanother coating surface (in the case of recoating applications).

The coating composition can be applied to a surface by any suitablecoating technique, including spraying, rolling, brushing, or spreading.The composition can be applied in a single coat, or in multiplesequential coats (e.g., in two coats or in three coats) as required fora particular application. Generally, the coating composition is allowedto dry under ambient conditions. However, in certain embodiments, thecoating composition can be dried, for example, by heating and/or bycirculating air over the coating.

The thickness of the resultant coating compositions can vary dependingupon the application of the coating. For example, the coating can have adry thickness of at least 0.5 microns, (e.g., at least 10 microns, atleast 15 microns, at least 20 microns, at least 25 microns, at least 30microns, at least 40 microns, at least 50 microns, at least 60 microns,at least 75 microns, at least 85 microns, at least 100 microns, at least150 microns, at least 200 microns, at least 250 microns, at least 300microns, at least 350 microns, at least 400 microns, at least 450microns, or at least 500 microns. In some instances, the coatingcompositions has a dry thickness of less than 500 microns (e.g., 450microns or less, 400 microns or less, 350 microns or less, 300 micronsor less, 250 microns or less, 200 microns or less, 150 microns or less,100 microns or less, 75 microns or less, 50 microns or less, 40 micronsor less, 30 microns or less, 25 microns or less, or 20 microns or less.In some embodiments, the coating compositions has a dry thickness ofbetween 0.5 microns and 500 microns, from 0.5 microns to 250 microns,from 0.5 microns to 75 microns, or from 5 microns to 75 microns.

As described herein, the coating compositions when dried, exhibit UVreflectance, visible light reflectance, IR reflectance, or a combinationthereof. In some embodiments, the dried coating compositions exhibit UVreflectance at a wavelength from 100 nm to 400 nm of at least 10%, atleast 25%, at least 30%, at least 35%, at least 40%, at least 45%, atleast 50%, at least 55%, at least 60%, or at least 70% or greater. Insome embodiments, the dried coating compositions exhibit UV reflectanceat a wavelength from 100 nm to 400 nm of from 10% to 99%, from 10% to90%, from 10% to 80%, or from 30% to 85%.

In some embodiments, the coating compositions when dried, exhibit IRreflectance at a wavelength from 800 nm to 10 μm (or from 800 to 5 μm)of at least 10%, at least 25%, at least 30%, at least 35%, at least 40%,at least 45%, at least 50%, at least 55%, at least 60%, or at least 70%or greater. In some embodiments, the dried coating compositions exhibitIR reflectance at a wavelength from 800 nm to 10 μm (or from 800 to 5μm) of from 10% to 99%, from 10% to 90%, from 10% to 80%, or from 30% to85.

In some embodiments, the coating compositions form wet films havingimproved opacity. For example, wet films having a thickness of 75 μm,can exhibit a light scattering coefficient of greater than 1 S/mil, orgreater than 3 S/mil, and an absorption coefficient of less than 0.02 K,as determined according to BS EN ISO 6504-1. In specific embodiments,the film formed from the paint composition having a thickness of 75 μmcan have a contrast ratio of at least 90% (e.g., 91% or greater, 92% orgreater, 93% or greater, 94% or greater, 95% or greater, 95% or greater,or greater than 96%). In some embodiments, the coating compositionshaving improved opacity when dried, exhibit reflectance at a wavelengthfrom 100 nm to 800 nm (or from 100 to 400 nm) of at least 10%, at least25%, at least 30%, at least 35%, at least 40%, at least 45%, at least50%, at least 55%, at least 60%, or at least 70% or greater.

Methods of Making the Spheres

Methods of making the coating compositions are described, for example inU.S. Ser. No. 16/126,338 (or PCT/US2018/050168) and Ser. No. 16/126,346(or PCT/US2018/050175), which are incorporated herein by reference intheir entirety.

Briefly, the porous metal oxide spheres can be prepared with the use ofa sacrificial polymeric particle. For example, an aqueous colloiddispersion containing sacrificial polymer particles and a metal oxide isprepared, the polymer particles typically being nano-scaled. The aqueouscolloidal dispersion is mixed with a continuous oil phase, for instancewithin a microfluidic device or vibrating nozzle techniques, to producea water-in-oil emulsion. Emulsion aqueous droplets are prepared,collected and dried to form spheres containing sacrificial polymerparticles and metal oxide. The sacrificial polymer particles (e.g.,nanoparticles or nanospheres) are then removed, for instance viacalcination, to provide spherical metal oxide particles (spheres),typically micron-scaled containing a high degree of porosity and porestypically nano-scaled. The porous metal oxide spheres may containuniform pore diameters, a result of the sacrificial polymer particlesbeing spherical and monodisperse. In some cases, the porous metal oxidespheres are sintered, resulting in a continuous solid structure which isthermally and mechanically stable. Suitable sacrificial polymerparticles include thermoplastic polymers. For example, sacrificialpolymer particles are selected from the group consisting ofpoly(meth)acrylic acid, poly(meth)acrylates, polystyrenes,polyacrylamides, polyvinyl alcohol, polyvinyl acetate, polyesters,polyurethanes, polyethylene, polypropylene, polylactic acid,polyacrylonitrile, polyvinyl ethers, derivatives thereof, salts thereof,copolymers thereof and combinations thereof. For example, thesacrificial polymer particles are selected from the group consisting ofpolymethyl methacrylate, polyethyl methacrylate, poly(n-butylmethacrylate), polystyrene, poly(chloro-styrene),poly(alpha-methylstyrene), poly(N-methylolacrylamide), styrene/methylmethacrylate copolymer, polyalkylated acrylate, polyhydroxyl acrylate,polyamino acrylate, polycyanoacrylate, polyfluorinated acrylate,poly(N-methylolacrylamide), polyacrylic acid, polymethacrylic acid,methyl methacrylate/ethyl acrylate/acrylic acid copolymer,styrene/methyl methacrylate/acrylic acid copolymer, polyvinyl acetate,polyvinylpyrrolidone, polyvinylcaprolactone, polyvinylcaprolactam,derivatives thereof, salts thereof, and combinations thereof. The wt/wt(weight/weight) ratio of sacrificial polymer particles to metal oxidecan be from 0.1:1 to 10:1.

Sacrificial polymer removal may be performed for example viacalcination, pyrolysis or with a solvent (solvent removal). Calcinationis performed in some embodiments at temperatures of at least about 200°C., at least about 500° C., at least about 1000° C., from about 200° C.to about 1200° C. or from about 200° C. to about 700° C. The calciningcan be for a suitable period, e.g., from about 0.1 hour to about 12hours or from about 1 hour to about 8.0 hours. In other embodiments, thecalcining can be for at least about 0.1 hour, at least about 1 hour, atleast about 5 hours or at least about 10 hours.

The spheres derived from the polymer spheres can be prepared frompolydisperse polymer particles comprising forming a liquid solution ordispersion of monodisperse polymer particles; forming at least onefurther liquid solution or dispersion of monodisperse polymer particles;mixing each of the solutions or dispersions together; forming dropletsof the mixture; and drying the droplets to provide polymer spherescomprising polydisperse polymer particles. A microwave or an oven can beused for drying the droplets which can be done under vacuum or in thepresence of a desiccant or a combination thereof.

In an alternate embodiment, the solutions or dispersions can be mixedtogether and spray-dried to provide the spheres derived from the polymerspheres.

Methods of Making the Coating Compositions

The polymer binder in the coating compositions can be prepared by anypolymerization method known in the art. In some embodiments, the polymerbinder can be prepared by a dispersion, a mini-emulsion, or an emulsionpolymerization.

Methods of making the coating compositions can include mixing thepolymer binder with one or more or the spheres described herein.

Methods for protecting a substrate against UV or IR-radiation are alsoprovided. The method can include applying a UV coating composition or anIR coating composition as described herein to the surface. The surfacecan be glass, metal, wood, plastic, concrete, vinyl, ceramic material oranother coating layer applied on such surface.

By way of non-limiting illustration, examples of certain embodiments ofthe present disclosure are given below.

EXAMPLES Example 1: Preparation of UV Protective Coatings

UV protective coatings including clear coatings for wood can be preparedby mixing a sphere having a particle diameter of from 1 to 10 microns,from 1 to 5 microns, or from 1 to 3 microns and voids of from 50 to 400nm or from 50 to 200 nm with a polymer binder, water, and optionally adefoamer, a pigment dispersant agent, one or multiple rheology modifyingpolymers, a light stabilizer, a wetting agent, a fungicide/mildewcideagent, an inorganic pigment extender, and an organic or inorganic lightabsorbing pigment.

It is believed that the spheres in the UV protective coatings willmitigate effects from UV radiation, offering improved coatingperformance and can be used to replace existing technologies used in UVprotective coatings.

Example 2: Preparation of Coatings with Improved Opacity

Coatings having improved opacity such as paints can be prepared bymixing a sphere having a particle diameter of from 1 to 100 microns orfrom 1 to 10 microns and voids of from 50 to 800 nm, from 50 to 400 nm,or from 50 to 200 nm with a polymer binder, water, and optionally adefoamer, a pigment dispersant agent, one or multiple rheology modifyingpolymers, a light stabilizer, a wetting agent, a fungicide/mildewcideagent, an inorganic pigment extender, an organic or inorganic lightabsorbing pigment, and an organic or inorganic light scattering pigment(e.g. TiO₂).

It is believed that the light scattering efficiency of the coatings willexceed that of rutile titanium dioxide, which is currently used incoatings for light scattering characteristics.

Example 3: Preparation of IR Protective Coatings

IR protective coatings including can be prepared by mixing a spherehaving a particle diameter of 5 microns or greater (such as from 5microns to 100 microns) and voids of from 400 to 10000 nm or from 400 to1000 nm with a polymer binder, water, and optionally a defoamer, apigment dispersant agent, one or multiple rheology modifying polymers, alight stabilizer, a wetting agent, a fungicide/mildewcide agent, aninorganic pigment extender, an organic or inorganic light absorbingpigment, and an organic or inorganic light scattering pigment (e.g.TiO₂).

It is believed that the spheres in the IR protective coatings willmitigate effects from IR radiation, preventing heat transfer into thebody of the coating and the substrate.

Embodiments of the Coating Compositions

Coating compositions that exhibit UV reflectance, visible lightreflectance, IR reflectance, or a combination thereof.

The coating compositions of the preceding embodiment, wherein thecoating composition comprises a polymer binder; and a sphere (e.g.,microsphere) selected from porous metal oxide spheres (e.g.,microspheres) formed from metal oxide particles (e.g., nanoparticles)and having an average porosity of from 0.10 to 0.80 or from 0.10 to0.90; polymer spheres (e.g., microspheres) formed from a multimodaldistribution of polymer particles (e.g., nanoparticles); or mixturesthereof.

The coating compositions of any one of the preceding embodiments,wherein the polymer binder comprises a polymer selected from acrylichomopolymers, styrene-acrylic-based copolymers, styrene-butadiene-basedcopolymers, styrene-butadiene-styrene block copolymers, vinylacrylic-based copolymers, ethylene vinyl acetate-based copolymers,polychloroprene, alkyd resin, polyester resins, polyurethane resins,silicone resins, petroleum resins, epoxy resins, or blends thereof.

The coating compositions of any one of the preceding embodiments,wherein the polymer binder is present in an amount of from greater than0% to 99.9% by weight, from 5% to 99.9% by weight, or from 10% to 95% byweight, based on a dry weight of the coating composition.

The coating compositions of any one of the preceding embodiments,wherein the sphere has an average particle size diameter of 100 micronsor less, or from 1 micron to 100 microns.

The coating compositions of any one of the preceding embodiments,wherein the sphere comprises the porous metal oxide spheres.

The coating compositions of any one of the preceding embodiments,wherein the porous metal oxide spheres comprise from 60% to 99.9% byweight metal oxide, based on a total weight of the porous metal oxidespheres.

The coating compositions of any one of the preceding embodiments,wherein the metal oxide is selected from the group consisting of silica,titania, alumina, zirconia, ceria, iron oxides, zinc oxide, andcombinations thereof, such as titania or silica.

The coating compositions of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average porosity of from0.20 to 0.70, from 0.40 to about 0.65, or from 0.45 to about 0.55.

The coating compositions of any one of the preceding embodiments,wherein the porous metal oxide spheres have a multimodal distribution ofpore sizes, such as a bimodal distribution of pore sizes.

The coating compositions of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average pore diameterfrom 50 nm to 10 μm, from 50 nm to 5 μm, from 50 nm to 2.5 μm, or from50 nm to 1 μm.

The coating compositions of any one of the preceding embodiments,wherein the sphere comprises the polymer spheres.

The coating compositions of any one of the preceding embodiments,wherein the polymer spheres are formed from a multimodal distribution ofpore sizes, such as a bimodal distribution of pore sizes.

The coating compositions of any one of the preceding embodiments,wherein the polymer spheres comprise a polymer selected from the groupconsisting of poly(meth)acrylic acid, poly(meth)acrylates, polystyrenes,polyacrylamides, polyethylene, polypropylene, polylactic acid,polyacrylonitrile, blends thereof, salts thereof, and copolymersthereof.

The coating compositions of any one of the preceding embodiments,wherein the coating composition further comprises one or more pigmentsor mineral fillers, such as those selected from clay, kaolin, mica,titanium dioxide, talc, natural silica, synthetic silica, naturalsilicates, synthetic silicates, feldspars, nepheline syenite,wollastonite, diatomite, barite, glass, and calcium carbonate,bentonite, attapulgite, zeolite, or mixtures thereof.

The coating compositions of any one of the preceding embodiments,wherein the sphere and the one or more pigments or mineral fillers arepresent in the composition from greater than 0% to 90% by weight or from0.1% to 60% by weight, based on a total weight of the coatingcomposition.

The coating compositions of any one of the preceding embodiments,further comprising a pigment dispersant, an inorganic or organic filler,a pigment extender, an adhesion enhancer, a film forming aid, adefoamer, a thickener, a light stabilizer, a wetting agent, a biocide, atackifier, or a combination thereof.

The coating compositions of any one of the preceding embodiments,wherein the coating composition is an aqueous composition.

A UV reflective composition formed from a coating composition of any oneof the preceding embodiments.

The UV reflective composition of the preceding embodiment, wherein theUV reflective composition exhibits UV reflectance within a wavelengthrange from 100 nm to 400 nm.

The UV reflective composition of any one of the preceding embodiments,wherein a film formed from the UV reflective composition exhibits UVreflectance at a wavelength from 100 nm to 400 nm of at least 10%, atleast 20%, at least 40%, or at least 50%.

The UV reflective composition of any one of the preceding embodiments,comprising a sphere including porous metal oxide spheres formed frommetal oxide particles, wherein the sphere has an average particle sizediameter of from 1 micron to 10 microns, from 1 micron to 5 microns, orfrom 1 micron to 3 microns.

The UV reflective composition of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average pore diameter offrom 50 nm to 400 nm or from 50 nm to 200 nm.

The UV reflective composition of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average porosity of from0.10 to 0.90, 0.10 to 0.80, from 0.20 to 0.70, from 0.40 to 0.65, orfrom 0.45 to 0.55.

The UV reflective composition of any one of the preceding embodiments,comprising porous metal oxide spheres having an average diameter of from1 micron to 10 microns, from 1 micron to 5 microns, or from 1 micron to3 microns; an average porosity of from 0.20 to 0.70 or from 0.45 to0.55; and an average pore diameter of from 50 nm to 400 nm or from 50 nmto 200 nm.

The UV reflective composition of any one of the preceding embodiments,comprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, blends thereof, or copolymersthereof.

The UV reflective composition of any one of the preceding embodiments,further comprising one or more UV absorbers, such as selected from ahydroxy-phenyl-benzotriaziole, a hydroxy-phenyl-triazine, ahydroxyl-benzophenone, an oxanilide, a cyanoacrylate, a malonate and amixture thereof.

The UV reflective composition of any one of the preceding embodiments,wherein the UV reflective composition is a clear coating.

A coating having improved opacity formed from a coating composition ofany one of the preceding embodiments.

The coating having improved opacity of the preceding embodiment,comprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, blends thereof, or copolymersthereof.

The coating having improved opacity of any one of the precedingembodiments, comprising a sphere selected from porous metal oxidespheres formed from metal oxide particles, polymer spheres formed from amultimodal distribution of polymer particles, or a mixture thereof.

The coating having improved opacity of any one of the precedingembodiments, wherein the sphere has an average particle size diameter of100 microns or less, from 1 micron to 100 microns, or from 1 micron to10 microns, and an average porosity of from or from 0.40 to 0.65 or from0.45 to 0.55.

The coating having improved opacity of any one of the precedingembodiments, wherein the sphere includes porous metal oxide sphereshaving an average pore diameter of from 50 nm to 800 nm or from 50 nm to400 nm.

The coating having improved opacity of any one of the precedingembodiments, comprising porous metal oxide spheres having an averagediameter of from 1 microns to 100 microns or from 0.5 microns to 100microns; an average porosity of from 0.20 to 0.70 or from 0.45 to 0.55;and an average pore diameter of from 50 nm to 800 nm or from 50 nm to400 nm.

The coating having improved opacity of any one of the precedingembodiments, wherein the porous metal oxide spheres comprises a metaloxide selected from the group consisting of silica, titania, andcombinations thereof.

The coating having improved opacity of any one of the precedingembodiments, wherein the sphere is present in an amount of from 5% to90% by weight or from 5% to 80% by weight of the paint composition.

The coating having improved opacity of any one of the precedingembodiments, wherein a wet film formed from the coating having athickness of 75 μm, exhibits a light scattering coefficient of greaterthan 1 S/mil or greater than 3 S/mil, and an absorption coefficient ofless than 0.02 K, as determined according to BS EN ISO 6504-1.

The coating having improved opacity of any one of the precedingembodiments, wherein a film formed from the paint composition having athickness of 75 μm has a contrast ratio of at least 90% or greater than96%.

The coating having improved opacity of any one of the precedingembodiments, wherein the coating is a paint composition.

The coating having improved opacity of any one of the precedingembodiments, wherein the paint composition is selected from an aqueousbased paint or an oil based paint, such as selected from an industrialpaint or an architectural paint for interior and exterior applications.

An IR reflective composition formed from a coating composition of anyone of the preceding embodiments.

The IR reflective composition of the preceding embodiment, wherein theIR reflective composition exhibits IR reflectance within a wavelengthrange from 800 nm to 10 μm, from 800 nm to 2.5 microns, or from 800 nmto 1 micron.

The IR reflective composition of any one of the preceding embodiments,wherein a film formed from the IR reflective composition exhibits IRreflectance at a wavelength from 800 nm to 10 μm of at least 10%, atleast 20%, at least 40%, or at least 50%.

The IR reflective composition of any one of the preceding embodiments,comprising a sphere selected from porous metal oxide spheres formed frommetal oxide particles, polymer spheres formed from a multimodaldistribution of polymer particles, or a mixture thereof.

The IR reflective composition of any one of the preceding embodiments,comprising a sphere including porous metal oxide spheres formed frommetal oxide particles, wherein the sphere has an average particle sizediameter of from 5 microns or greater or from 5 microns to 100 microns.

The IR reflective composition of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average pore diameterfrom 400 nm to 10 microns, from 400 nm to 5 microns, from 400 nm to 2.5microns, from 400 nm to 1 micron, or from 400 nm to 700 nm.

The IR reflective composition of any one of the preceding embodiments,wherein the porous metal oxide spheres have an average porosity of from0.10 to 0.90, from 0.10 to 0.80, from 0.20 to 0.70, from 0.40 to 0.65,or from 0.45 to 0.55.

The IR reflective composition of any one of the preceding embodiments,comprising porous metal oxide spheres having an average diameter of from5 microns to 100 microns; an average porosity of from 0.20 to 0.70 orfrom 0.45 to 0.55; and an average pore diameter of from 400 nm to 5microns, from 400 nm to 2.5 microns, or from 400 nm to 1 micron.

The IR reflective composition of any one of the preceding embodiments,comprising a polymer selected from acrylic homopolymers,styrene-acrylic-based copolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, blends thereof, or copolymersthereof.

The IR reflective composition of any one of the preceding embodiments,wherein the IR reflective composition is an architectural coating, or apaint or an ink.

A coating or film obtained by applying a composition according to anyone of the preceding embodiments on a substrate.

The coating or film of any one of the preceding embodiments, having athickness of from 0.5 to 500 microns, from 5 to 75 microns, or 30microns or less.

The coating or film of any one of the preceding embodiments, wherein thesubstrate is an architectural structure, glass, metal, wood, plastic,concrete, vinyl, or ceramic material or another coating layer applied onsuch a substrate.

Methods for protecting a substrate against IR-radiation, UV-radiation,or a combination thereof comprising applying a coating compositionaccording to any one of the preceding embodiments.

The compositions and methods of the appended claims are not limited inscope by the specific compositions and methods described herein, whichare intended as illustrations of a few aspects of the claims and anycompositions and methods that are functionally equivalent are intendedto fall within the scope of the claims. Various modifications of thecompositions and methods in addition to those shown and described hereinare intended to fall within the scope of the appended claims. Further,while only certain representative compositions and method stepsdisclosed herein are specifically described, other combinations of thecompositions and method steps also are intended to fall within the scopeof the appended claims, even if not specifically recited. Thus, acombination of steps, elements, components, or constituents may beexplicitly mentioned herein or less, however, other combinations ofsteps, elements, components, and constituents are included, even thoughnot explicitly stated. The term “comprising”, and variations thereof asused herein is used synonymously with the term “including” andvariations thereof and are open, non-limiting terms. Although the terms“comprising” and “including” have been used herein to describe variousembodiments, the terms “consisting essentially of” and “consisting of”can be used in place of “comprising” and “including” to provide for morespecific embodiments of the invention and are also disclosed. Other thanin the examples, or where otherwise noted, all numbers expressingquantities of ingredients, reaction conditions, and so forth used in thespecification and claims are to be understood at the very least, and notas an attempt to limit the application of the doctrine of equivalents tothe scope of the claims, to be construed in light of the number ofsignificant digits and ordinary rounding approaches.

1.-22. (canceled)
 23. A coating composition comprising: a polymerbinder; and a sphere selected from porous metal oxide spheres formedfrom metal oxide particles and having an average porosity of from 0.10to 0.90; polymer spheres formed from a multimodal distribution ofpolymer particles; or mixtures thereof, wherein the sphere has anaverage particle size diameter of from 1 micron to 100 microns, andwherein the coating composition when dried exhibits a UV reflectancewithin a wavelength from 100 nm to 400 nm; a visible light reflectancewithin a wavelength of from 400 to 800 nm; an IR reflectance within awavelength from 800 nm to 10 μm; or a combination thereof.
 24. Thecoating composition of claim 23, wherein the polymer binder comprises apolymer selected from acrylic homopolymers, styrene-acrylic-basedcopolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene block copolymers, vinyl acrylic-basedcopolymers, ethylene vinyl acetate-based copolymers, polychloroprene,alkyd resin, polyester resins, polyurethane resins, silicone resins,petroleum resins, epoxy resins, or blends thereof.
 25. The coatingcomposition of claim 23, wherein the coating composition is an aqueouscomposition.
 26. The coating composition of claim 23, wherein the spherecomprises the porous metal oxide spheres.
 27. The coating composition ofclaim 26, wherein the porous metal oxide spheres have a multimodaldistribution of pore sizes, or a bimodal distribution of pore sizes. 28.The coating composition of claim 26, wherein the composition is a UVreflective composition, and the porous metal oxide spheres have anaverage diameter from 1 micron to 3 microns; an average porosity from0.45 to 0.55; and an average pore diameter from 50 nm to 400 nm.
 29. Thecoating composition of claim 26, wherein the coating composition is anIR reflective composition, and the porous metal oxide spheres have anaverage diameter of from greater than 5 microns to 100 microns; anaverage porosity from 0.45 to 0.55; and an average pore diameter from400 nm to 1 micron.
 30. The coating composition of claim 26, wherein theporous metal oxide spheres comprise from 60% to 99.9% by weight metaloxide, based on a total weight of the porous metal oxide spheres. 31.The coating composition of claim 30, wherein the metal oxide is selectedfrom the group consisting of silica, titania, alumina, zirconia, ceria,iron oxides, zinc oxide, and combinations thereof.
 32. The coatingcomposition of claim 23, wherein the sphere comprises the polymerspheres.
 33. A film derived from a composition of claim 23, wherein thefilm exhibits a UV reflectance at a wavelength from 100 nm to 400 nm ofat least 20%.
 34. The film of claim 33, wherein the film having athickness of 75 microns, exhibits a contrast ratio of at least 90% andthe film exhibits an IR reflectance at a wavelength from 800 nm to 1 μm,at least 20%.
 35. A clear coating composition comprising: a polymerselected from acrylic homopolymers, styrene-acrylic-based copolymers,styrene-butadiene-based copolymers, styrene-butadiene-styrenecopolymers, vinyl acrylic copolymers, ethylene vinyl acetate copolymers,polychloroprene, blends thereof, thereof; and a sphere comprising porousmetal oxide spheres formed from metal oxide particles, wherein thesphere has an average particle size diameter from 1 micron to 3 microns,and wherein the clear coating composition when dried exhibits a UVreflectance at a wavelength range from 100 nm to 400 nm.
 36. The clearcoating composition of claim 35, further comprising one or more UVabsorbers, selected from a hydroxy-phenyl-benzotriaziole, ahydroxy-phenyl-triazine, a hydroxyl-benzophenone, an oxanilide, acyanoacrylate, a malonate, or a mixture thereof.
 37. A method forprotecting a substrate against UV-radiation, the method comprisingapplying the clear coating composition according to claim 35 to thesubstrate.
 38. A paint composition comprising: a polymer selected fromacrylic homopolymers, styrene-acrylic-based copolymers,styrene-butadiene-based copolymers, styrene-butadiene-styrenecopolymers, vinyl acrylic copolymers, ethylene vinyl acetate copolymers,polychloroprene, blends thereof; and a sphere selected from porous metaloxide spheres formed from metal oxide particles, polymer spheres formedfrom a multimodal distribution of polymer particles, or a mixturethereof, wherein the sphere has an average particle size diameter from 1micron to 10 microns, and an average porosity of from 0.40 to 0.65. 39.The paint composition of claim 38, wherein a wet film formed from thepaint composition having a thickness of 75 μm, exhibits a lightscattering coefficient of greater than 3 S/mil, and an absorptioncoefficient of less than 0.02 K, as determined according to BS EN ISO6504-1.
 40. An infrared reflecting coating composition comprising: apolymer selected from acrylic homopolymers, styrene-acrylic-basedcopolymers, styrene-butadiene-based copolymers,styrene-butadiene-styrene copolymers, vinyl acrylic copolymers, ethylenevinyl acetate copolymers, polychloroprene, alkyd resin, polyesterresins, polyurethane resins, silicone resins, petroleum resins, epoxyresins, blends thereof; and a sphere selected from porous metal oxidespheres formed from metal oxide particles, polymer spheres formed from amultimodal distribution of polymer particles, or a mixture thereof,wherein the sphere has an average particle size diameter from 5 micronsto 100 microns and an average porosity of from or from 0.40 to 0.65, andwherein the coating composition when dried exhibits an IR reflectance ata wavelength range from 800 nm to 1 micron.
 41. The infrared reflectingcoating composition of claim 40, wherein the porous metal oxide sphereshave an average pore diameter from 400 nm to 1 micron.
 42. The coatingcomposition of claim 23, comprising: a polymer binder; and porous metaloxide spheres formed from metal oxide particles, wherein the coatingcomposition when dried exhibits a UV reflectance within a wavelengthfrom 100 nm to 400 nm; a visible light reflectance within a wavelengthof from 400 to 800 nm; an IR reflectance within a wavelength from 800 nmto 10 μm; or a combination thereof, wherein the composition is a UVreflective composition, and the porous metal oxide spheres have anaverage diameter from 1 micron to 100 microns; an average porosity from0.45 to 0.55; and an average pore diameter from 50 nm to 400 nm, andwherein the coating composition is an aqueous composition.
 43. Thecoating composition of claim 23, comprising: a polymer binder; andporous metal oxide spheres formed from metal oxide particles, whereinthe coating composition when dried exhibits a UV reflectance within awavelength from 100 nm to 400 nm; a visible light reflectance within awavelength of from 400 to 800 nm; an IR reflectance within a wavelengthfrom 800 nm to 10 μm; or a combination thereof, wherein the compositionis a UV reflective composition, and the porous metal oxide spheres havean average diameter from 1 micron to 10 microns; an average porosityfrom 0.45 to 0.55; and an average pore diameter from 50 nm to 400 nm,and wherein the coating composition is an aqueous composition.
 44. Thecoating composition of claim 23, comprising: a polymer binder; andporous metal oxide spheres formed from metal oxide particles, whereinthe coating composition when dried exhibits a UV reflectance within awavelength from 100 nm to 400 nm; a visible light reflectance within awavelength of from 400 to 800 nm; an IR reflectance within a wavelengthfrom 800 nm to 10 μm; or a combination thereof, wherein the compositionis a UV reflective composition, and the porous metal oxide spheres havean average diameter from 1 micron to 3 microns; an average porosity from0.10 to 0.90; and an average pore diameter from 50 nm to 400 nm, andwherein the coating composition is an aqueous composition.
 45. Thecoating composition of claim 23, comprising: a polymer binder; and asphere selected from porous metal oxide spheres formed from metal oxideparticles and having an average porosity of from 0.45 to 0.55; polymerspheres formed from a multimodal distribution of polymer particles; ormixtures thereof, wherein the coating composition when dried exhibits aUV reflectance within a wavelength from 100 nm to 400 nm; a visiblelight reflectance within a wavelength of from 400 to 800 nm; an IRreflectance within a wavelength from 800 nm to 10 μm; or a combinationthereof, wherein the composition is a UV reflective composition, and theporous metal oxide spheres have an average diameter from 1 micron to 3microns; an average porosity from 0.45 to 0.55; and an average porediameter from 50 nm to 400 nm, and wherein the coating composition is anaqueous composition.
 46. The coating composition of claim 23,comprising: a polymer binder; and a sphere selected from porous metaloxide spheres formed from metal oxide particles and having an averageporosity of from 0.10 to 0.90; polymer spheres formed from a multimodaldistribution of polymer particles; or mixtures thereof, wherein thesphere has an average particle size diameter of from 1 micron to 100microns, and wherein the coating composition when dried exhibits a UVreflectance within a wavelength from 100 nm to 400 nm; a visible lightreflectance within a wavelength of from 400 to 800 nm; an IR reflectancewithin a wavelength from 800 nm to 10 μm; or a combination thereof. andwherein the coating composition is an aqueous composition.